13 papers

Jorge E Chavarro

Professor, Medicine, Harvard Medical School

Disordered eating behaviors during adolescence and risk of endometriosis: a prospective cohort study

Thornburgh S et al., 2026 Fertility and sterility

Disordered eating behaviors may impact the gynecologic health of adolescents through effects on menstrual cycle function and body size; however, few studies have evaluated these associations. This study aimed to prospectively investigate the associations between individual disordered eating behaviors during adolescence and the risk of subsequent endometriosis diagnosis. Prospective, longitudinal cohort (1996-2021). Female participants (n = 11,773) from the Growing Up Today Study. Exposure: Frequency of binge eating, laxative use, and self-induced vomiting over the past year was self-reported on repeated questionnaires during follow-up. Physician-diagnosed endometriosis was reported on repeated questionnaires during follow-up. Multivariable logistic regression models with generalized estimating equations were used to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CIs). Over 25 years of follow-up, we identified 269 incident cases of endometriosis (2.3%), 190 of which were reported as laparoscopically confirmed. A total of 32% of girls reported ever binge eating, 14% reported self-induced vomiting to lose weight, and 9% reported ever using laxatives to lose weight. The odds of a laparoscopically-confirmed endometriosis diagnosis were more than three-fold higher (aOR = 3.07; 95% CI 1.74, 5.40) for girls who cumulatively reported self-induced vomiting more than monthly during follow-up, compared with girls who never reported self-induced vomiting. Cumulative exposure to binge eating during follow-up was not associated with diagnosis of laparoscopically-confirmed endometriosis; however, girls who reported the highest ever engagement in binge eating of weekly or more had 52% lower (aOR = 0.47; 95% CI 0.25, 0.90) odds of laparoscopically-confirmed endometriosis, compared with girls who reported less than weekly binge eating. Laxative use was not strongly associated with endometriosis diagnosis, although estimates were imprecise. Females with a greater frequency of self-induced vomiting were more likely to be diagnosed with endometriosis during follow-up, whereas girls with a history of frequent binge eating had a lower likelihood of endometriosis diagnosis. We found no association between laxative use and endometriosis.

Nutrition and Metabolic Health · Dietary Patterns

Dietary patterns and age at menarche in a prospective study of girls in the USA

Davis CP et al., 2025 Hum Reprod Open Access

Are dietary patterns associated with age at menarche after accounting for BMI-for-age (BMIz) and height? We observed associations between both the Alternative Healthy Eating Index (AHEI) and the Empirical Dietary Inflammatory Pattern (EDIP) and age at menarche. Dietary patterns have been sparsely examined in relation to age at menarche and no studies have examined the association between the AHEI, a healthier diet, and EDIP, a pro-inflammatory diet, and menarche. STUDY DESIGN, SIZE, The Growing Up Today Study (GUTS) is a prospective cohort of children ages 9-14 years at study enrollment. GUTS enrolled in two waves with enrollment beginning in 1996 (GUTS1) and 2004 (GUTS2). For this analysis, GUTS1 and GUTS2 participants were followed through 2001 and 2008, respectively. PARTICIPANTS/MATERIALS, SETTING, We included 7530 participants who completed food frequency questionnaire(s) (FFQ) prior to menarche who then self-reported age at menarche during study follow-up. Cox proportional hazard models were used to calculate multivariable hazard ratios (HRs) and 95% CIs for the associations between two dietary patterns, the AHEI and EDIP, and age at menarche, with and without adjustment for time-varying BMIz and height. MAIN Six thousand nine hundred ninety-two participants (93%) reported menarche during the study period. On average, participants completed the baseline FFQ 1.75 years prior to menarche. Participants in the highest quintile of AHEI diet score (indicating a healthier diet) were 8% less likely to attain menarche within the next month compared to those in the lowest quintile (95% CI = 0.85-0.99; Ptrend = 0.03). This association remained after adjustment for BMIz and height (corresponding HR = 0.93; 95% CI = 0.86-1.00; Ptrend = 0.04). Participants in the highest quintile of the EDIP score (i.e. most inflammatory diet), were 15% more likely to attain menarche in the next month relative to those in the lowest quintile (95% CI = 1.06-1.25; Ptrend = 0.0004), and the association remained following adjustment for BMIz and height (corresponding HR = 1.15; 95% CI = 1.06-1.25; Ptrend = 0.0004). LIMITATIONS, Self-reported questionnaires are subject to some error; however, given our prospective study design it is likely this error is non-differential with respect to the outcome. Our findings of an association between both the AHEI and EDIP and age at menarche indicate that diet quality may play a role in age at menarche independent of BMI or height. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Breast Cancer Research Foundation. The GUTS is supported by the National Institutes of Health U01 HL145386. C.P.D. was supported by National Institutes of Health T32 CA094880. The authors have no conflicts of interest to disclose. N/A.

Lifespan Health · Cycle as a Lifespan Health Marker

Menstrual cycle regularity and length across the reproductive lifespan and risk of premature mortality: prospective cohort study

Wang YX et al., 2020 BMJ Open Access

AbstractObjectiveTo evaluate whether irregular or long menstrual cycles throughout the life course are associated with all cause and cause specific premature mortality (age <70 years). Prospective cohort study. Nurses’ Health Study II (1993-2017).Participants79 505 premenopausal women without a history of cardiovascular disease, cancer, or diabetes and who reported the usual length and regularity of their menstrual cycles at ages 14-17 years, 18-22 years, and 29-46 years. Hazard ratios and 95% confidence intervals for all cause and cause specific premature mortality (death before age 70 years) were estimated from multivariable Cox proportional hazards models. During 24 years of follow-up, 1975 premature deaths were documented, including 894 from cancer and 172 from cardiovascular disease. Women who reported always having irregular menstrual cycles experienced higher mortality rates during follow-up than women who reported very regular cycles in the same age ranges. The crude mortality rate per 1000 person years of follow-up for women reporting very regular cycles and women reporting always irregular cycles were 1.05 and 1.23 for cycle characteristics at ages 14-17 years, 1.00 and 1.37 for cycle characteristics at ages 18-22 years, and 1.00 and 1.68 for cycle characteristics at ages 29-46 years. The corresponding multivariable adjusted hazard ratios for premature death during follow-up were 1.18 (95% confidence interval 1.02 to 1.37), 1.37 (1.09 to 1.73), and 1.39 (1.14 to 1.70), respectively. Similarly, women who reported that their usual cycle length was 40 days or more at ages 18-22 years and 29-46 years were more likely to die prematurely than women who reported a usual cycle length of 26-31 days in the same age ranges (1.34, 1.06 to 1.69; and 1.40, 1.17 to 1.68, respectively). These relations were strongest for deaths related to cardiovascular disease. The higher mortality associated with long and irregular menstrual cycles was slightly stronger among current smokers. Irregular and long menstrual cycles in adolescence and adulthood are associated with a greater risk of premature mortality (age <70 years). This relation is slightly stronger among women who smoke.

Study Design · Cohort Studies

The Preconception Period analysis of Risks and Exposures Influencing health and Development (PrePARED) consortium

Harville EW et al., 2019 Paediatr Perinat Epidemiol Open Access

Preconception health may have intergenerational influences. We have formed the PrePARED (Preconception Period Analysis of Risks and Exposures influencing health and Development) research consortium to address methodological, conceptual, and generalisability gaps in the literature. The consortium will investigate the effects of preconception exposures on four sets of outcomes: (1) fertility and miscarriage; (2) pregnancy-related conditions; (3) perinatal and child health; and (4) adult health outcomes. A study is eligible if it has data measured for at least one preconception time point, has a minimum of selected core data, and is open to collaboration and data harmonisation. The included studies are a mix of studies following women or couples intending to conceive, general-health cohorts that cover the reproductive years, and pregnancy/child cohort studies that have been linked with preconception data. The majority of the participating studies are prospective cohorts, but a few are clinical trials or record linkages. Data analysis will begin with harmonisation of data collected across cohorts. Initial areas of interest include nutrition and obesity; tobacco, marijuana, and other substance use; and cardiovascular risk factors. Twenty-three cohorts with data on almost 200 000 women have combined to form this consortium, begun in 2018. Twelve studies are of women or couples actively planning pregnancy, and six are general-population cohorts that cover the reproductive years; the remainder have some other design. The primary focus for four was cardiovascular health, eight was fertility, one was environmental exposures, three was child health, and the remainder general women's health. Among other cohorts assessed for inclusion, the most common reason for ineligibility was lack of prospectively collected preconception data. The consortium will serve as a resource for research in many subject areas related to preconception health, with implications for science, practice, and policy.

Fertility and Outcomes · Conception After Excision

Endometriosis and Risk of Adverse Pregnancy Outcomes

Farland LV et al., 2019 Obstetrics &amp; Gynecology Open Access

To investigate the relationship between endometriosis and adverse pregnancy outcomes. Women between ages 25 and 42 years in 1989 (n=116,429) reported detailed information on pregnancies and reproductive health at baseline and every 2 years thereafter in the Nurses' Health Study II, a cohort study. In 2009, they completed a detailed, pregnancy-focused questionnaire. A total of 196,722 pregnancies were reported. Adverse pregnancy outcomes included spontaneous abortion, ectopic pregnancy, stillbirth, gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (preeclampsia or gestational hypertension), preterm birth, and low birth weight. We estimated the relative risks (RRs) and 95% CIs of adverse pregnancy outcomes comparing pregnancies in women with and without a history of laparoscopically confirmed endometriosis using multivariable log-binomial regression, with generalized estimating equations to account for multiple pregnancies per woman. Endometriosis was associated with a greater risk of pregnancy loss (spontaneous abortion: RR 1.40, 95% CI 1.31–1.49; ectopic pregnancy: RR 1.46, 95% CI 1.19–1.80). Endometriosis was also associated with a greater risk of GDM (RR 1.35, 95% CI 1.11–1.63) and hypertensive disorders of pregnancy (RR 1.30, 95% CI 1.16–1.45). We observed an association between laparoscopically confirmed endometriosis and several adverse pregnancy outcomes. Future research should focus on the potential biological pathways underlying these relationships to inform screening or preventive interventions.

Nutrition and Metabolic Health · Dietary Patterns

Fruit and vegetable consumption and risk of endometriosis

Harris HR et al., 2018 Human reproduction (Oxford, England) Open Access

Is there an association between intake of fruits and vegetables and risk of laparoscopically confirmed endometriosis? Higher intake of fruits, particularly citrus fruits, is associated with a lower risk of endometriosis. Two case-control studies have examined the associations between fruit and vegetable intake and endometriosis risk with contrasting results. Diets rich in fruits and vegetables include higher levels of pro-vitamin A nutrients (alpha-carotene, beta-carotene, beta-cryptoxanthin) and women with endometriosis have been reported to have lower intake of vitamin A than women without endometriosis. STUDY DESIGN SIZE, A prospective cohort study using data collected from 70 835 premenopausal women from 1991 to 2013 as part of the Nurses' Health Study II cohort. PARTICIPANTS/MATERIALS, SETTING, Diet was assessed with a validated food frequency questionnaire (FFQ) every 4 years. Cases were restricted to laparoscopically confirmed endometriosis. Cox proportional hazards models were used to calculate rate ratios (RR) and 95% CI. MAIN During 840 012 person-years of follow-up, 2609 incident cases of laparoscopically confirmed endometriosis were reported (incidence rate = 311 per 100 000 person-years). We observed a non-linear inverse association between higher fruit consumption and risk of laparoscopically confirmed endometriosis (Psignificance of the curve = 0.005). This inverse association was particularly evident for citrus fruits. Women consuming ≥1 servings of citrus fruits/day had a 22% lower endometriosis risk (95% CI = 0.69-0.89; Ptrend = 0.004) compared to those consuming <1 serving/week. No association was observed between total vegetable intake and endometriosis risk. However, women consuming ≥1 servings/day cruciferous vegetables had a 13% higher risk of endometriosis (95% CI = 0.95-1.34; Ptrend = 0.03) compared to those consuming <1 serving/week. Of the nutrients examined, only beta-cryptoxanthin intake was significantly associated with lower endometriosis risk (RR fifth quintile = 0.88; 95% CI = 0.78-1.00; Ptrend = 0.02). LIMITATIONS Some error in the self-reporting of dietary intake is expected, however, use of a validated FFQ and examining diet prospectively across multiple time points, make it unlikely that this non-differential misclassification strongly influenced the results. Our findings suggest that a higher intake of fruits, particularly citrus fruits, is associated with a lower risk of endometriosis, and beta-cryptoxanthin in these foods may partially explain this association. In contrast to what we hypothesized, consumption of some vegetables increased endometriosis risk which may indicate a role of gastrointestinal symptoms in both the presentation and exacerbation of endometriosis-related pain; however, it is not clear what components of these foods might underlie the observed associations. Future studies examining dietary patterns that consider different combinations of food intake may help clarify these associations. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by research grants HD4854, HD52473 and HD57210 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and grant P30 DK046200 from the National Institute of Diabetes and Digestive and Kidney Diseases. The Nurses' Health Study II is supported by the Public Health Service grant UM1 CA176726 from the National Cancer Institute, National Institutes of Health. HRH is supported by the National Cancer Institute, National Institutes of Health (K22 CA193860). No competing interests. n/a.

Nutrition and Metabolic Health · Dietary Patterns

Diet and fertility: a review

Gaskins AJ et al., 2017 Am J Obstet Gynecol Open Access

The literature on the relationship between diet and human fertility has greatly expanded over the last decade, resulting in the identification of a few clear patterns. Intake of supplemental folic acid, particularly at doses higher than those recommended for the prevention of neural tube defects, has been consistently related to lower frequency of infertility, lower risk of pregnancy loss, and greater success in infertility treatment. On the other hand and despite promising evidence from animal models, vitamin D does not appear to exert an important role in human fertility in the absence of deficiency. Antioxidant supplementation does not appear to offer any benefits to women undergoing infertility treatment, but it appears to be beneficial when it is the male partner who is supplemented. However, the available evidence does not allow discerning which specific antioxidants, or at which doses, are responsible for this benefit. Long-chain omega-3 fatty acids appear to improve female fertility, although it remains unclear to what extent contamination of shared food sources, such as fish with high levels of environmental toxicants, can dampen this benefit. Lastly, adherence to healthy diets favoring seafood, poultry, whole grains, fruits, and vegetables are related to better fertility in women and better semen quality in men. The cumulative evidence has also piled against popular hypotheses. Dairy and soy, once proposed as reproductive toxicants, have not been consistently related to poor fertility. In fact, soy and soy supplements appear to exert a beneficial effect among women undergoing infertility treatment. Similarly, because data from large, high-quality studies continue to accumulate, the evidence of a potentially deleterious effect of moderate alcohol and caffeine intake on the ability to become pregnant seems less solid than it once did. While a complete picture of the role of nutrition on fertility is far from complete, much progress has been made. The most salient gaps in the current evidence include jointly considering female and male diets and testing the most consistent findings in randomized trials.

Nutrition and Metabolic Health · Dietary Patterns

Processed meat intake is unfavorably and fish intake favorably associated with semen quality indicators among men attending a fertility clinic

Afeiche MC et al., 2014 The Journal of nutrition Open Access

Emerging literature suggests that men's diets may affect spermatogenesis as reflected in semen quality indicators, but literature on the relation between meat intake and semen quality is limited. Our objective was to prospectively examine the relation between meat intake and indicators of semen quality. Men in subfertile couples presenting for evaluation at the Massachusetts General Hospital Fertility Center were invited to participate in an ongoing study of environmental factors and fertility. A total of 155 men completed a validated food-frequency questionnaire and subsequently provided 338 semen samples over an 18-mo period from 2007-2012. We used linear mixed regression models to examine the relation between meat intake and semen quality indicators (total sperm count, sperm concentration, progressive motility, morphology, and semen volume) while adjusting for potential confounders and accounting for within-person variability across repeat semen samples. Among the 155 men (median age: 36.1 y; 83% white, non-Hispanic), processed meat intake was inversely related to sperm morphology. Men in the highest quartile of processed meat intake had, on average, 1.7 percentage units (95% CI: -3.3, -0.04) fewer morphologically normal sperm than men in the lowest quartile of intake (P-trend = 0.02). Fish intake was related to higher sperm count and percentage of morphologically normal sperm. The adjusted mean total sperm count increased from 102 million (95% CI: 80, 131) in the lowest quartile to 168 million (95% CI: 136, 207) sperm in the highest quartile of fish intake (P-trend = 0.005). Similarly, the adjusted mean percentages of morphologically normal sperm for men in increasing quartiles of fish intake were 5.9 (95% CI: 5.0, 6.8), 5.3 (95% CI: 4.4, 6.3), 6.3 (95% CI: 5.2, 7.4), and 7.5 (95% CI: 6.5, 8.5) (P-trend = 0.01). Consuming fish may have a positive impact on sperm counts and morphology, particularly when consumed instead of processed red meats.

Male Factor Causes · Lifestyle and Environment

BMI in relation to sperm count: an updated systematic review and collaborative meta-analysis

Sermondade N et al., 2013 Human reproduction update Open Access

BACKGROUND The global obesity epidemic has paralleled a decrease in semen quality. Yet, the association between obesity and sperm parameters remains controversial. The purpose of this report was to update the evidence on the association between BMI and sperm count through a systematic review with meta-analysis. METHODS A systematic review of available literature (with no language restriction) was performed to investigate the impact of BMI on sperm count. Relevant studies published until June 2012 were identified from a Pubmed and EMBASE search. We also included unpublished data (n = 717 men) obtained from the Infertility Center of Bondy, France. Abstracts of relevant articles were examined and studies that could be included in this review were retrieved. Authors of relevant studies for the meta-analysis were contacted by email and asked to provide standardized data. RESULTS A total of 21 studies were included in the meta-analysis, resulting in a sample of 13 077 men from the general population and attending fertility clinics. Data were stratified according to the total sperm count as normozoospermia, oligozoospermia and azoospermia. Standardized weighted mean differences in sperm concentration did not differ significantly across BMI categories. There was a J-shaped relationship between BMI categories and risk of oligozoospermia or azoospermia. Compared with men of normal weight, the odds ratio (95% confidence interval) for oligozoospermia or azoospermia was 1.15 (0.93-1.43) for underweight, 1.11 (1.01-1.21) for overweight, 1.28 (1.06-1.55) for obese and 2.04 (1.59-2.62) for morbidly obese men. CONCLUSIONS Overweight and obesity were associated with an increased prevalence of azoospermia or oligozoospermia. The main limitation of this report is that studied populations varied, with men recruited from both the general population and infertile couples. Whether weight normalization could improve sperm parameters should be evaluated further.

Nutrition and Metabolic Health · Dietary Patterns

Dietary patterns and semen quality in young men

Gaskins AJ et al., 2012 Human reproduction (Oxford, England) Open Access

Are different dietary patterns associated with semen parameters in young men? The consumption of a Prudent dietary pattern was significantly associated with higher progressive sperm motility and unrelated to sperm concentration and morphology. The consumption of a Western dietary pattern was unrelated to conventional semen quality parameters. Over the past decades there has been evidence of a concomitant decline in sperm and diet quality. Yet whether diet composition influences semen quality remains largely unexplored. STUDY DESIGN, SIZE, The Rochester Young Men's Study (n= 188) was a cross-sectional study conducted between 2009 and 2010 at the University of Rochester. PARTICIPANTS, SETTING, Men aged 18-22 years were included in this analysis. Diet was assessed via food frequency questionnaire and dietary patterns were identified by factor analysis. Linear regression was used to analyze the relation between diet patterns and conventional semen quality parameters (sperm concentration, progressive motility and morphology) adjusting for abstinence time, multivitamin use, race, smoking status, BMI, recruitment period, moderate-to-intense exercise and total calorie intake. Two dietary patterns were identified by factor analysis. The 'Western' pattern was characterized by high intake of red and processed meat, refined grains, pizza, snacks, high-energy drinks and sweets. The 'Prudent' pattern was characterized by high intake of fish, chicken, fruit, vegetables, legumes and whole grains. The Prudent pattern was positively associated with percent progressively motile sperm in multivariate models (P-trend = 0.04). Men in the highest quartile of the Prudent diet had 11.3% (95% CI 1.3, 21.3) higher % progressively motile sperm compared with men in the lowest quartile. The Prudent pattern was unrelated to sperm concentration and morphology. The Western pattern was not associated with any semen parameter. This was a cross-sectional and observational study, which limited our ability to determine causality of diet on semen quality parameters. Our findings support the suggestion that a diet rich in fruits, vegetables, chicken, fish and whole grains may be an inexpensive and safe way to improve at least one measure of semen quality. The authors are supported by NIH grant T32DK007703-16 and P30DK46200 and European Union DEER Grant 212844. The authors have no competing interests to declare.

Nutrition and Metabolic Health · Dietary Patterns

Diet and lifestyle in the prevention of ovulatory disorder infertility

Chavarro JE et al., 2007 Obstetrics and gynecology

To evaluate the relation of a dietary pattern and other lifestyle practices to risk of ovulatory disorder infertility. We followed a cohort of 17,544 women without a history of infertility for 8 years as they tried to become pregnant or became pregnant. A dietary score based on factors previously related to lower ovulatory disorder infertility (higher consumption of monounsaturated rather than trans fats, vegetable rather than animal protein sources, low glycemic carbohydrates, high fat dairy, multivitamins, and iron from plants and supplements) and other lifestyle information was prospectively related to the incidence of infertility. Increasing adherence to a "fertility diet" pattern was associated with a lower risk of ovulatory disorder infertility. The multivariable-adjusted relative risk of ovulatory disorder infertility comparing women in the highest with women in the lowest quintile of the "fertility diet" pattern score was 0.34 (95% confidence interval 0.23-0.48; P for trend<.001). This inverse relation was similar in subgroups defined by women's age, parity, and body weight. A combination of five or more low-risk lifestyle factors, including diet, weight control, and physical activity was associated with a 69% lower risk of ovulatory disorder infertility and an estimated population attributable risk of 66% (95% confidence interval 29-86%). Following a "fertility diet" pattern may favorably influence fertility in otherwise healthy women. Further, the majority of infertility cases due to ovulation disorders may be preventable through modifications of diet and lifestyle. II.

Nutrition and Metabolic Health · Dietary Patterns

Dietary fatty acid intakes and the risk of ovulatory infertility

Chavarro JE et al., 2007 The American Journal of Clinical Nutrition

Pharmacologic activation of the peroxisome proliferator-activated receptor gamma (PPAR-gamma) improves ovulatory function in women with polycystic ovary syndrome, and specific dietary fatty acids can affect PPAR-gamma activity. The objective of the study was to assess whether the intakes of total fat, cholesterol, and major types of fatty acids affect the risk of ovulatory infertility. We conducted a prospective cohort study of 18 555 married, premenopausal women without a history of infertility who attempted a pregnancy or became pregnant between 1991 and 1999. Diet was assessed twice during follow-up by using a food-frequency questionnaire. During follow-up, 438 incidents of ovulatory infertility were reported. In logistic regression analyses, intakes of total fat, cholesterol, and most types of fatty acids were not related to ovulatory infertility. Each 2% increase in the intake of energy from trans unsaturated fats, as opposed to that from carbohydrates, was associated with a 73% greater risk of ovulatory infertility after adjustment for known and suspected risk factors for this condition [relative risk (RR) = 1.73; 95% CI: 1.09, 2.73]. Obtaining 2% of energy intake from trans fats rather than from n-6 polyunsaturated fats was associated with a similar increase in the risk of ovulatory infertility (RR = 1.79; 95% CI: 1.11, 2.89). In addition, obtaining 2% of energy from trans fats rather than from monounsaturated fats was associated with a more than doubled risk of ovulatory infertility (RR = 2.31; 95% CI: 1.09, 4.87).Conclusiontrans Unsaturated fats may increase the risk of ovulatory infertility when consumed instead of carbohydrates or unsaturated fats commonly found in nonhydrogenated vegetable oils.